Classic & Vintage - Suntour Shifter Boss Mod to Standard? NEED HELP
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01-01-12, 08:25 PM
I have seen others run into this problem before and have seen different answers. 86 or 85 Raleigh Super Course USA with Suntour shifter bosses. I would like to modify the boss to fit the shifters I have. I have four sets of Suntour shifters and all are standard mount (Campy/Shimano??). Two power ratchet one Pro friction and one 6-7speed Pro and none of the bolts are the right thread to go on the boss. What I would like to do is thread the boss with a tap but none of my taps match the standard shifter bolts. What is the thread size 5M X .8 ????
Can you buy the right size at Sears, Lowes, Home Depot, or do I have to go to a speacilty shop.
01-01-12, 08:31 PM
232210232211232209 Last of the paint falling to the ground, I love spray can paint stripper. Boss unmodified and after grinding, filling to fit the shifters.
01-01-12, 09:30 PM
you have shimano type-A 4.5M bosses.
let me know how your experiment works out. you are going to need to tap the threads to M5 x .8 as you stated.
i'm in the same boat, but i have shifters and fortunately they work well. others have modified cable stops instead of the bosses to use bar end shifters
01-01-12, 09:31 PM
also, in order to get that tap, you are going to have to order it online or get it from a specialty shop unless you want to buy a whole set.
01-01-12, 09:33 PM
In your shoes I'd grind those off and silver braze in some new ones. It's actually a fairly straightforward job. John Waite is a framebuilder in Apple Valley, and I'm sure he'd do it for you, if you don't feel up to it.
WRT to the tap, if you decide to go that route, bear in mind that the hole doesn't go through the tubing, so you'll want a bottoming tap rather than a standard style.
01-01-12, 10:32 PM
Thanks to everyone.
Would it kill the frame to drill a hole through the tube in the hole for the shifter boss. Then I could use a regular tap. ???
01-01-12, 10:35 PM
Probably not. But adding holes to a frame just so you can save a few dollars on a tap seems like false economy to me.
01-02-12, 12:26 AM
another option is to just leave them as is and use a clamp. you can get clamps that will fit your shifters on ebay.
01-03-12, 12:33 AM
Thanks to every one who helpped. Brazing on new shifter bosses would ruin the chrome, so that is a no-go. Drilled through the boss and tube with a 4mm bit and ran the 5m X .8 tap in to finish it off. Now that I can screw the shifters on I added a little JB Weld to the bosses to keeps things from spinning around. Don't know about long term use but this will get me on the road.
232333232334 I know they don't look straight in the picture but they are.
01-03-12, 12:37 AM
That looks like it is shaping up to be a stunner of a bike.
01-03-12, 12:51 AM
You know the secret
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